<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
		<style>
			.BigBox{
				width: 100px;
			}
			.smallBox{
				float: left;
				width:50px;
				height: 100px;
			}
			.smallBox:nth-child(odd){
				margin-top: 60px;
				background: red;
			}
			.smallBox:nth-child(even){
				margin-top: 40px;
				background: blue;
			}
		</style>
	</head>
	<body>
		<div class="BigBox">
			<div class="smallBox"></div>
			<div class="smallBox"></div>
			<div class="smallBox"></div>
			<div class="smallBox"></div>
		</div>
	</body>
</html>
